The effects of ethanol on the nervous system have been studied for many years by a number of investigators, yet the precise mechanism of action still remains to be seen. The proposed study is aimed at elucidating the mechanism whereby ethanol exerts its acute effects on neurons of the central nervous system. It has become increasingly clear that voltage-activated calcium channels are blocked by ethanol and that GABA receptor-channel complexes are stimulated by ethanol. Patch clamp techniques, both whole cell and single channel recording versions, will be applied to cultured neurons to assess the effects of ethanol on these channels. Cultured neuroblastoma cells (N1E-115) are endowed with two types of calcium channels, and the effects of ethanol to suppress both types of channels will be analyzed at both whole cell and single channel levels. There is some evidence to indicate that ethanol action on calcium channels is exerted via delta opioid receptor. Interactions of opioid agonists and antagonists with ethanol will be examined using neuroblastoma- glioma hybrid NG108-15 cells to determine the validity of this hypothesis. GABA receptor-channel complexes are known to be stimulated by ethanol. Both whole cell and single channel recording experiments for GABA-activated channels will be performed using primary cultured neurons isolated from the dorsal root ganglion, the spinal cord, and the hippocampal slices. There are at least two subtypes, chloride channels associated with GABAA receptors and potassium channels associated with GABAB receptors. The effects of ethanol on both types of channels at the whole cell and single channel levels will be examined and analyzed. Ion channels activated by glycine, another inhibitory transmitter, will also be studied for ethanol action. The interactions of ethanol with calcium channels and GABA- activated channels can account for its acute effect, and the results of proposed research will provide the basis for the mechanisms of alcoholism and for approaches to prevent and cure the disorder.